good luck

Hello,

sorry for being absent for while and not reading here...

I noticed this thread just before the question to buy Smarttire sensors again or to change the system to a cheaper one. So I decided to change (my summer-tires also need new sensors...)...
I choose the Waeco TPMS (www.waeco.com) stuff for only 100 Euro and with 4 sensors but without a display (which I, and I guess you guys too, don't need) and it would be good to have a system from a vendor "with a name" (in 5-6 years if you need new sensors - but the batteries could be exchanged easily).

Preamble (32 bits) - The preamble is a series of 31 logic ‘1’ bits followed by a single logic ‘0’ bit (FFFE in hexadecimal), used to recognize the RF transmission as a valid TX message.

....

no ... the Preamble is 16 bits (FFFE) (your digitrace screenshots also shows only 15 bits at 1)...

The Waeco system also transmits on 433Mhz AM with a differential manchester coding... which looks like (!) that:
which gives for example a: FFFE 001C40F7 81 30 DA 01 E258
with Robby's findings these can be interpreted to a tire pressure of 2,2bar (I have a normal car!) and 8°C (which perfectly fits into a german winter) and 218 of 255 (new sensors with new batteries!) (How does the CRC fit inside ? I didn't get it to work...)

So I guess the Waeco system is compatible ?

This all sounds too good ? Then have a look at the PCB of the receiver :
The receiver is this shielded box connected with 7 pins to the main pcb... it gets 5V+ , ANT (external antenna!) and GND and devlievers the signal and the field strength...
easy to desolder ? no saw needed.. only a soldering iron...

I've taken the display and receivers apart to identify the communication protocol between the received and the display, looks like it uses a single wire LIN bus protocol, as the receiver uses a 6258 IC and the display uses a 6259-2 IC.

I noticed the PIC Robby used for his USB interface also supports LIN bus. If we can decode the communication, we might be able to modify Robby's PCB to communicate with this receiver, offering a somewhat affordable solution.

TruckPC - gutted, being used for test setup
BoatPC - All in 1 in cuddy, N7 using VNC on dash, RR
BlazerPC - Nexus 7 with Timur's USBROM

Okay, how do I get a complete setup, ready to go, minus the wheel sensors? Or do I need a COMPLETE kit with reciever, and piggy-back it on a custom PCB?
You guys have done a tremendous job with this!! I wish I could easily incorporate it into my CarPC

I am starting to wonder if the tpms sensors are interchangable. What happens with the Valet unit if you need more sensors? Can you use another sensor from a different company?

I have boxes of OEM TMPS recievers sitting next to me (Honda, Toyota, etc). None of them look like the after-market ones though. All have intergrated boards. But I guess they do not need all the fancy external lcd stuff though since it all goes to the ECM.

I've taken the display and receivers apart to identify the communication protocol between the received and the display, looks like it uses a single wire LIN bus protocol, as the receiver uses a 6258 IC and the display uses a 6259-2 IC.

I noticed the PIC Robby used for his USB interface also supports LIN bus. If we can decode the communication, we might be able to modify Robby's PCB to communicate with this receiver, offering a somewhat affordable solution.

too much circumstances...
try to connect at the receiver module !
Pinlayout: from left to right looking at the back:
12345 678 90

I noticed this thread just before the question to buy Smarttire sensors again or to change the system to a cheaper one. So I decided to change (my summer-tires also need new sensors...)...
I choose the Waeco TPMS (www.waeco.com) stuff for only 100 Euro and with 4 sensors but without a display (which I, and I guess you guys too, don't need) and it would be good to have a system from a vendor "with a name" (in 5-6 years if you need new sensors - but the batteries could be exchanged easily).!